Coating compositions containing tetramethyl cyclobutanediol

ABSTRACT

Disclosed are solvent borne thermosetting coating compositions that contain a curable polyester resin blended with an acrylic copolymer, a crosslinker, and a solvent. The polyester resin contains 2,2,4,4-tetramethyl-1,3-cyclobutanediol and exhibits good dry time, compatibility with acrylic resins, sag resistance and hardness development in a coating composition. The coating compositions can be used to prepare clear coat or pigmented coatings for automotive OEM, auto refinish, and other applications.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a Continuation application of United StatesNon-Provisional application Ser. No. 13/435,347, filed Mar. 30, 2012,which is a Continuation application of United States Non-Provisionalapplication Ser. No. 12/367,113, filed Feb. 6, 2009 (now U.S. Pat. No.8,168,721), both of which are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The invention pertains to thermosetting coating compositions. Moreparticularly, this invention pertains to thermosetting coatingcompositions comprising a curable polyester containing2,2,4,4-tetramethyl-1,3-cyclobutanediol, an acrylic copolymer, acrosslinker, and a solvent.

DETAILED DESCRIPTION

Acrylics and polyesters are common types of resins used in themanufacture of solvent borne thermosetting coatings. Acrylics are knownfor their excellent hardness, fast dry times, scratch, stain, chemical,and humidity resistance, and outdoor durability. Acrylic coatings,however, often lack flexibility and require large amounts of solvent inthe coating formulation to achieve a practical application viscosity.The high solvent requirement for acrylics makes it difficult to satisfycoating VOC (“volatile organic compound”) content regulations asmandated by various federal and state air quality organizations.

By contrast, polyesters are ideally suited to formulate low VOC contentor “high solids” coatings and provide a good balance of performanceproperties. Polyesters, however, typically do not weather as well asacrylics. Blends of acrylic and polyester resins can be used to achievehigh solids solventborne thermosetting coatings with desirableproperties. Some illustrative examples of coating compositionscomprising blends of acrylic and polyester resins are the subject ofU.S. Pat. Nos. 4,076,766; 4,322,508; 4,338,379; 4,397,989; 4,751,267;and 4,716,200.

Polyester resins can be used to replace a portion of the acrylic resinin a coating formulation to improve certain performance properties. Forexample, the presence of a polyester may help lower VOC content,increase gloss, improve the flexibility of the coating, or a combinationof one or more of these properties. The polyester, however, also mayhave the undesirable effect of slowing dry time. Sag resistance,hardness and hardness related properties of the coating may becompromised as well.

For example, polyester resins containing neopentyl glycol (abbreviatedherein as “NPG”) and high levels of isophthalic acid (abbreviated hereinas “IPA”) generally exhibit good gloss, hardness, stain resistance andchemical resistance. Polyesters with high IPA content, however, exhibitpoor compatibility when blended with acrylic resins.

Incompatibility of polyester/acrylic blends will manifest itself throughphase separation, precipitation of the resins from solution and varyingdegrees of poor clarity that range from opaque to hazy solutions. Theseconditions are highly undesirable and result in poor storage stabilityof the resin solution and the coating formulated therefrom. The coatingmay experience a viscosity increase, phase separation, agglomeration ofingredients, etc., that will result in a higher application viscosity,poor appearance and poor mechanical properties of the cured film.

The compatibility of the polyester sometimes can be improved byincorporating various modifying diols, dicarboxylic acids, andanhydrides in the resin formulation. Examples of these modifying diolsand dicarboxylic acids include 1,6-hexanediol (abbreviated herein as“HD”), 2,2,4-trimethyl-1,3-pentanediol (abbreviated herein as “TMPD”),2-butyl-2-ethyl-1,3-propanediol (abbreviated herein as “BEPD”), adipicacid (abbreviated herein as “AD”), 1,4-cyclohexanedicarboxylic acid(abbreviated herein as “CHDA”), and hexahydrophthalic anhydride(abbreviated herein as “HHPA”). Although these monomers can improvecompatibility, they often produce polyesters that slow dry time, lowersag resistance and decrease coating hardness and the desirableproperties associated with higher hardness.

Polyester resins are needed, therefore, that form compatible blends withacrylic resins yet maintain the desirable hardness properties exhibitedby the acrylic resins alone in high solids coating compositions. We havefound that polyester resins prepared from2,2,4,4-tetramethyl-1,3-cyclobutanediol exhibit good compatibility withacrylic resins, even in the presence of high aromatic dicarboxylic acidcontent.

The present invention provides a solvent-borne thermosetting coatingcomposition comprising a curable polyester prepared from2,2,4,4-tetramethyl-1,3-cyclobutanediol, an acrylic copolymer, acrosslinker and a solvent. Therefore, in one embodiment, our inventionprovides a thermosetting coating composition, comprising:

-   (A). about 2 to about 50 weight percent, based on the total weight    of (A), (B), and (C) of a curable polyester, comprising    -   i. diacid residues, comprising about 20 to 100 mole percent,        based on the total moles of diacid residues, of the residues of        isophthalic acid and about 80 to about 0 mole of the residues of        adipic acid;    -   ii. diol residues, comprising about 10 to 100 mole percent,        based on the total moles of diol residues, of the residues of        2,2,4,4-tetramethyl-1,3-cyclobutanediol; and    -   iii. about 2 to about 40 mole percent of the residues of at        least one polyol, based on the total moles of diol and polyol        residues;    -   wherein the curable polyester has a number average molecular        weight of about 500 to about 10,000 daltons, a glass transition        temperature of about −35° C. to about 100° C., a hydroxyl number        of about 20 to about 300 mg KOH/g of polyester, and an acid        number of 0 to about 80 mg KOH/g of polyester;-   (B). about 25 to about 88 weight percent, based on the total weight    of (A), (B), and (C) of at least one acrylic copolymer of    ethylenically unsaturated monomers comprising at least one hydroxyl,    epoxy, carboxyl, blocked phenol, or acetoacetoxy functional group;    and-   (C). about 10 to about 50 weight percent, based on the total weight    of (A), (B), and (C), of at least one crosslinker comprising at    least one compound reactive with a carboxylic acid or a hydroxyl    group;-   (D). about 10 to about 60 weight percent, based on the total weight    of (A), (B), (C), and (D) of at least one nonaqueous solvent.    The coating compositions of our invention exhibit an improvement in    dry time, sag resistance and hardness development in comparison to    an acrylic blended with typical polyester resin formulations such    as, for example, those containing NPG/IPA, or commercially available    polyesters recommended for such applications. Our coating    compositions may be used to prepare clear coat or pigmented coatings    used in auto OEM, auto refinish, transportation, aerospace,    maintenance, marine, machinery and equipment, general metal,    appliance, metal furniture, plastic and building/construction    coating applications.

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, reaction conditions,and so forth used in the specification and claims are to be understoodas being modified in all instances by the term “about.” Unless indicatedto the contrary, the numerical parameters set forth in the followingspecification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, each numerical parameter should beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques. Further, the ranges stated inthis disclosure and the claims are intended to include the entire rangespecifically and not just the endpoint(s). For example, a range statedto be 0 to 10 is intended to disclose all whole numbers between 0 and 10such as, for example 1, 2, 3, 4, etc., all fractional numbers between 0and 10, for example 1.5, 2.3, 4.57, 6.1113, etc., and the endpoints 0and 10. Also, a range associated with chemical substituent groups suchas, for example, “C₁ to C₅ hydrocarbons”, is intended to specificallyinclude and disclose C₁ and C₅ hydrocarbons as well as C₂, C₃, and C₄hydrocarbons.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in itsrespective testing measurements.

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include their plural referents unless the contextclearly dictates otherwise. For example, a reference to a “polyester,” a“dicarboxylic acid”, a “residue” is synonymous with “at least one” or“one or more” polyesters, dicarboxylic acids, or residues and is thusintended to refer to a plurality of polyesters, dicarboxylic acids, orresidues. In addition, references to a composition containing orincluding “an” ingredient or “a” polyester is intended to include otheringredients or other polyesters, respectively, in addition to the onenamed. The terms “containing” or “including” are intended to besynonymous with the term “comprising”, meaning that at least the namedcompound, element, particle, or method step, etc., is present in thecomposition or article or method, but does not exclude the presence ofother compounds, catalysts, materials, particles, method steps, etc.,even if the other such compounds, material, particles, method steps,etc., have the same function as what is named, unless expressly excludedin the claims.

Also, it is to be understood that the mention of one or more processsteps does not preclude the presence of additional process steps beforeor after the combined recited steps or intervening process steps betweenthose steps expressly identified. Moreover, the lettering of processsteps or ingredients is a convenient means for identifying discreteactivities or ingredients and the recited lettering can be arranged inany sequence, unless otherwise indicated.

The term “curable polyester”, as used herein, is synonymous with theterm “resin” and intended to mean a thermosetting surface coatingpolymer prepared by the polycondensation of one or more acid components,diol components, and polyol components. The curable polyester of thepresent invention is a thermoset polymer and is particularly suitable asa resin for solvent-based coatings. This polyester has a low molecularweight, typically about 500 to about 10,000 daltons, and would not besuitable for the fabrication of films, sheets, and other shaped objectsby extrusion, casting, blow molding, and other thermoforming processescommonly used for high molecular weight thermoplastic polymers. Thepolyester has reactive functional groups, typically hydroxyl groups orcarboxyl groups for the purpose of later reacting with crosslinkers in acoating formulation. The functional group is controlled by having eitherexcess diol or acid (from dicarboxylic acid or tricarboxylic acid) inthe polyester resin composition. The desired crosslinking pathway willdetermine whether the polyester resin will be hydroxyl-terminated orcarboxylic acid-terminated. The concept is known to those skilled in theart and described, for example, in Organic Coatings Science andTechnology, 2nd ed., p. 246-257, by Z. Wicks, F. Jones, and S. Pappas,Wiley, New York, 1999.

Typically, the acid component comprises at least one dicarboxylic acidand may, optionally, include mono- and polybasic carboxylic acids. Forexample, the curable polyester may be prepared from an acid componentcomprising an aromatic dicarboxylic acid such as, for example,isophthalic acid, an aliphatic or cycloaliphatic dicarboxylic acid suchas, for example, adipic acid or 1,3-cyclohexanedicarboxylic acid, or amixture of one or more aromatic, aliphatic, and cycloaliphatic acids.The diol component may comprise one or more aliphatic cycloaliphaticdiols such as, for example, 2,2,4,4-tetramethyl-1,3-cyclobutanediol,linear or branched aliphatic diols such as, for example, neopentylglycol, or aromatic diols such as, for example, p-xylenediol. Catalystsmay be used to accelerate the rate of the polycondensation reaction.Additional examples of each of the components of the curable polyesterinclude those known in the art, including those discussed below and invarious documents known in the art such as, for example, in Resins forSurface Coatings, Vol. III, p. 63-167, ed. by P. K. T. Oldring and G.Hayward, SITA Technology, London, UK, 1987.

The term “residue”, as used herein in reference to the polymers of theinvention, means any organic structure incorporated into a polymerthrough a polycondensation or ring opening reaction involving thecorresponding monomer. It will also be understood by persons havingordinary skill in the art, that the residues associated within thevarious curable polyesters of the invention can be derived from theparent monomer compound itself or any derivative of the parent compound.For example, the dicarboxylic acid residues referred to in the polymersof the invention may be derived from a dicarboxylic acid monomer or itsassociated acid halides, esters, salts, anhydrides, or mixtures thereof.Thus, as used herein, the term “dicarboxylic acid” is intended toinclude dicarboxylic acids and any derivative of a dicarboxylic acid,including its associated acid halides, esters, half-esters, salts,half-salts, anhydrides, mixed anhydrides, or mixtures thereof, useful ina polycondensation process with a diol to make a curable polyester.

The term “nonaqueous solvent” is intended to mean a solvent or mixtureof solvents made up substantially of one or more organic liquids. Thenonaqueous solvents of the present invention will typically contain 30weight percent or less water, based on the total weight of the solvent.Other examples of non-aqueous solvents include solvents containing 20weight percent or less, 10 weight percent or less, and 5 weight percentor less of water.

The thermosetting coating composition of the present invention comprisesabout 2 to about 50 weight percent, based on the total weights ofcomponents (A), (B), and (C), of a curable polyester that, in turn,comprises the an acid component, a diol component, and a polyolcomponent. The acid component comprises the residues of an aromaticdicarboxylic acid, an acyclic aliphatic dicarboxylic acid, an alicyclicdicarboxylic acid, or a combination thereof; the diol componentcomprises the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Forexample, in a general embodiment, the curable polyester comprises:

-   i. diacid residues, comprising about 20 to 100 mole percent, based    on the total moles of diacid residues, of the residues of at least    one aromatic diacid and about 80 to 0 mole percent of the residues    of at least one aliphatic diacid, alicyclic diacid, or a combination    thereof;-   ii. diol residues, comprising about 10 to 100 mole percent, based on    the total moles of diol residues, of the residues of    2,2,4,4-tetramethyl-1,3-cyclobutanediol; and-   iii. about 2 to about 40 mole percent of the residues of at least    one polyol, based on the total moles of diol and polyol residues;    -   wherein the curable polyester has a number average molecular        weight of        about 500 to about 10,000 daltons, a glass transition        temperature of about −35° C. to about 100° C., a hydroxyl number        of about 10 to about 300 mg KOH/g of polyester, and acid number        of 0 to about 80 mg potassium hydroxide KOH/g of polyester.

The curable polyester can comprise about 20 to 100 percent, based on thetotal moles of diacid residues, of the residues of at least one aromaticdiacid. Examples of aromatic diacids included, but are not limited to,phthalic acid, terephthalic acid, isophthalic acid,2,6-naphthalenedicarboxylic acid, or combinations thereof. The 1,4-,1,5-, and 2,7-isomers of naphthalenedicarboxylic acid or mixturesthereof may be used in addition to the 2,6-isomer. In addition, to thearomatic diacid residues, the curable polyester can comprise about 80 to0 mole percent of the residues of an acyclic aliphatic or alicyclicdiacid such as, for example, adipic acid, dodecanedioic acid, sebacicacid, azelaic acid, glutaric acid, maleic acid, fumaric acid, succinicacid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylicacid, hexahydrophthalic acid, tetrahydrophthalic acid, or combinationsthereof. If cis and trans isomers are possible, the alicyclic diacid maybe used as the pure cis, trans isomer or mixtures of cis-trans isomers.Some additional, non-limiting examples of the diacid component that thecurable polyester can comprise are as follows: (a) about 30 to 100 molepercent of the residues of isophthalic acid; (b) about 30 to 100 molepercent of the residues of isophthalic acid and about 70 to 0 molepercent of the residues of an aliphatic diacid; and (c) about 30 to 100mole percent of the residues of isophthalic acid and about 70 to 0 molepercent of the residues of an aliphatic diacid having 8 carbons or less.

In another example, the curable polyester can comprise about 20 to about80 mole percent, based on the total moles of diacid residues, of theresidues of isophthalic acid and about 80 to about 20 mole of theresidues of adipic acid. In another example, the diacid residuescomprise about 30 to about 70 mole percent of the residues ofisophthalic acid, about 70 to about 30 mole percent adipic acid. Instill another example, the diacid residues can comprise about 40 toabout 60 mole percent of the residues of isophthalic acid and about 60to about 40 mole percent of the residues of adipic acid. In addition tothe residues of isophthalic and adipic acids, the diacid residues mayfurther comprise up to 30 mole percent of the residues of at least onedicarboxylic acid chosen from phthalic acid, terephthalic acid,tetrachlorophthalic acid, dodecanedioic acid, sebacic acid, azelaicacid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylicacid, hexahydrophthalic acid, tetrahydrophthalic acid, maleic acid,fumaric acid, succinic acid, 2,6-naphthalenedicarboxylic acid, andglutaric acid.

In addition to the dicarboxylic residues described above, the acidcomponent of our inventive polyester composition may further comprisethe residues of a monocarboxylic acid or polybasic acid containing morethan 2 carboxylic acid groups. For example, the polyester may compriseresidues chosen from benzoic acid, acetic acid, propionic acid,tert-butyl benzoic acid, butanoic acid, trimellitic anhydride, or amixture thereof.

The curable polyester also comprises about 10 to 100 mole percent, basedon the total moles of diol residues, of the residues of2,2,4,4-tetramethyl-1,3-cyclobutanediol (abbreviated herein as “TMCD”).The TMCD may be used as the pure cis and trans isomer or as a mixture ofcis-trans isomers. Other examples of TMCD residue content in the curablepolyester are about 20 to 100 mole percent, about 30 to about 70 molepercent, about 40 to about 60 mole percent, and about 50 mole percent.The curable polyester optionally may comprise up to 90 mole percent ofthe residues other diols in combination with TMCD such as, for example,neopentyl glycol, ethylene glycol, propylene glycol, diethylene glycol,triethylene glycol, tetraethylene glycol, pentaethylene glycol,hexaethylene glycol, heptaethylene glycol, octaethylene glycol,nonaethylene glycol, decaethylene glycol, 1,3-propanediol,2,4-dimethyl-2-ethyl-hexane-1,3-diol, 2,2-dimethyl-1,2-propanediol,2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol,1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,2,2,4-tetramethyl-1,6-hexanediol, thiodiethanol,1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,1,4-cyclohexanedimethanol, 2,2,4-trimethyl 1,3-pentanediol,p-xylenediol, hydroxypivalyl hydroxypivalate, 1,10-decanediol andhydrogenated bisphenol A. For example, the curable polyester resins maycomprise the residues of neopentyl glycol in combination with TMCD.

The curable polyester comprises about 2 to about 40 mole percent of theresidues of at least one polyol, based on the total moles of diol andpolyol residues. These polyols may include acyclic aliphatic, alicyclic,and aryl alkyl polyols. Some specific examples of polyols include, butare not limited to, trimethylolpropane (TMP), pentaerythritol (PE),trimethylolethane (TME), erythritol, threitol, dipentaerythritol,sorbitol, glycerine, and the like. In one example, the curable polyestercan comprise about 3 to about 30 mole percent of the residues of atleast one polyol selected from trimethylolpropane, pentaerythritol,trimethylolethane, erythritol, threitol, dipentaerythritol, sorbitol,and glycerine. In another embodiment, the curable polyester comprisestrimethylolpropane.

The curable polyester of this invention has a hydroxyl number of about10 to about 300 mg KOH/g resin. Further examples of hydroxyl number areabout 20 to about 275, and about 30 to about 250. The curable polyesterhas an acid number of about 0 to about 50 mg KOH/g resin or, in otherexamples, about 2 to about 25, and about 2 to about 15. The curablepolyester has a number average molecular weight of about 400 daltons toabout 10,000 daltons. Additional examples of molecular weight ranges areabout 600 to about 7000, and about 800 to about 5000. The curablepolyester can have a glass transition temperature (abbreviated herein as“Tg”) of about −35° C. to about 100° C. Other representative examples ofTg ranges for the curable polyester are about −35 to about 80° C., about−35 to about 50° C., about −20 to about 50° C., about −35 to less than50° C., about −35 to about 49° C., about −35 to about 48° C., about −35to about 47° C., about −35 to about 46° C., about −35 to about 45° C.,about −35 to about 40° C.

Other representative compositions of the curable polyesters of thepresent invention are those comprising: (a) about 20 to about 80 molepercent, based on the total moles of diacid residues, of the residues ofisophthalic acid and about 80 to about 20 mole of the residues of adipicacid; about 20 to 100 mole percent, based on the total moles of diolresidues, of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol;and about 2 to about 40 mole percent of the residues of a polyol, basedon the total moles of diol and polyol residues in which the curablepolyester has a number average molecular weight of about 500 to about10,000 daltons, a glass transition temperature of about −35° C. to about100° C., a hydroxyl number of about 20 to about 300 mg KOH/g ofpolyester, and an acid number of 0 to about 80 mg KOH/g of polyester;and (b) about 20 to 80 mole percent of the residues of isophthalic acid,about 80 to about 20 mole percent of the residues of adipic acid, and 0to about 30 mole percent of the residues of at least one dicarboxylicacid chosen from phthalic acid, terephthalic acid, tetrachlorophthalicacid, dodecanedioic acid, sebacic acid, azelaic acid,1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid,hexahydrophthalic acid, tetrahydrophthalic acid, maleic acid, fumaricacid, succinic acid, 2,6-naphthalenedicarboxylic acid, and glutaricacid; and diol residues comprising about 20 to 100 mole percent of theresidues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol. This polyestershould be understood to include the various embodiments of diacids,diols, polyols, acid and hydroxyl numbers, and glass transitiontemperatures described previously. For example, the curable polyestermay comprise about 40 to about 60 mole percent of the residues of2,2,4,4-tetramethyl-1,3-cyclobutanediol, about 60 to 40 mole percent ofthe residues of neopentyl glycol and about 2 to about 40 mole percent ofthe residues of at least one polyol chosen from trimethylolpropane,pentaerythritol, trimethylolethane, erythritol, and dipentaerythritol.In another example, the diacid component can comprise about 30 to about70 mole percent of isophthalic acid and about 70 to about 30 molepercent of adipic acid, and the diol component can comprise about 20 to100 mole percent 2,2,4,4-tetramethyl-1,3-cyclobutanediol. In yet anotherexample, the curable polyester can comprise about 50 to about 100 molepercent of the residues of isophthalic acid, 0 to about 50 mole percentof the residues of adipic acid, about 100 mole percent of the residuesof 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 10 mole percent ofthe residues of trimethylolpropane. In this embodiment, the curablepolyester can have a hydroxyl number of about 30 to about 250 mgpotassium hydroxide per gram of polyester, an acid number of about 2 toabout 15 mg potassium hydroxide per gram of polyester, a number averagemolecular weight of about 700 to about 7000 daltons, and a Tg of about−20 to about 50° C. In still another example, the curable polyester maycomprise about 50 mole percent of the residues of isophthalic acid,about 50 mole percent of the residues of adipic acid, about 50 molepercent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol,about 50 mole percent of the residues of neopentyl glycol, and about 10mole percent of the residues of trimethylolpropane.

The curable polyester also may further comprise the residues of amonocarboxylic acid chosen from benzoic acid, acetic acid, propionicacid, tert-butyl benzoic acid, and butanoic acid, trimellitic anhydride,or a mixture thereof. In yet another example, the polyester of theinvention may have a hydroxyl number of about 30 to about 250 mgpotassium hydroxide per gram of polyester, an acid number of about 2 toabout 15 mg potassium hydroxide per gram of polyester, and a numberaverage molecular weight of about 700 to about 7000 daltons, and a Tg ofabout −20 to about 75° C.

The curable polyester component can be prepared by heating the reactantsuntil the desired molecular weight, acid number, or hydroxyl number isreached. Typically, the reactants are heated at a temperature of about150 to about 250° C. while recovering water from the mixture to producea curable polyester polyester having number average molecular weight ofabout 500 to about 10,000 daltons, a glass transition temperature ofabout −35° C. to about 100° C., a hydroxyl number of about 20 to about300 mg potassium hydroxide/g of polyester, or an acid number of 0 toabout 80 mg potassium hydroxide/g of polyester.

The reaction can be monitored by the collection of water (directcondensation) or alcohol (ester inter-change). The polyester typicallyis be prepared at a temperature range of about 150-250° C. and can beconducted at atmospheric pressure or under vacuum. In another example,the diacid and diol components of the polyester may be partially reactedbefore the polyol is added. Once the polyol is added to the reactionmixture, heating is continued until a target acid number is satisfied.

Alternatively, the curable polyester can be prepared in the presence ofa process solvent to help remove the water of esterification and topromote the synthesis of the polyester resin. The process solvent may beany process solvent known in the art used in the formation of apolyester resin. For example, the process solvent can be a hydrocarbonsolvent. In another example, the process solvent can comprise anaromatic hydrocarbon, such as, for example, xylene. The xylene can be apure isomer, or a mixture of ortho, meta, and para isomers. The amountof process solvent can be determined by routine experimentation as wouldbe understood by those skilled in the art. The process solvent can beadded in amounts ranging from about 0.5 to about 5 weight percent, basedon the total weight of reaction mixture.

Optionally, a catalyst may be used to promote the synthesis of thepolyester. The catalyst may be any catalyst known in the art useful forthe formation of polyester polymers. For example, the catalyst can be atin catalyst, such as, for example, Fascat 4100™ (available from ArkemaCorporation). The amount of catalyst added may be determined by routineexperimentation as understood by those skilled in the art. Preferably, acatalyst is added in amounts ranging from about 0.01 to about 1.00weight % based on the amount of reactants.

The coating composition also comprises about 25 to about 88 weightpercent, based on the total weight of components (A), (B), and (C) of atleast one acrylic copolymer of ethylenically unsaturated monomerscomprising at least one hydroxyl, epoxy, carboxyl, blocked phenol, oracetoacetoxy functional group. Thermosetting acrylic resins aretypically prepared by free radical polymerization in bulk or in asolvent. Representative free-radical initiators include, but are notlimited to, organic peroxides or azo compounds, such as benzoylperoxide, t-butyl hydroperoxide, t-butyl peroxide, t-butylperoxybenzoate, azobisisobutyronitrile, and2,2′-azobis(2,4-dimethyl)-valeronitrile. The reaction is preferablycarried out at the reflux temperature of the solvent used, which isgenerally higher than the thermal decomposition temperature of theinitiator employed. Suitable examples of preparation methods andcomponents of the acrylic resin include those known in the artincluding, but not limited to, those described above, and in Resins forSurface Coatings, Vol. II, p. 121-210, ed. by P. K. T. Oldring and G.Hayward, SITA Technology, London, UK, 1987.

The acrylic resin comprises acrylic monomers copolymerized with otherethylenically unsaturated monomers that contain reactive functionalgroups as listed above. Some common examples of acrylic monomersacrylate esters, methacrylate esters, (meth)acrylic acid, and acrylamidemonomers. Examples of ethylenically unsaturated monomers include, butare not limited to, mono- and dicarboxylic unsaturated acids, allylicmonomers, and vinyl compounds such as, for example, vinyl aromatichydrocarbons, vinyl aliphatic hydrocarbons, vinyl ethers, and vinylesters. Mono- and dicarboxylic unsaturated acids include fumaric acid,maleic acid or anhydride, haconic acid, citraconic acid, mesaconic acid,muconic acid, glutaconic acid, aconitic acid, hydrosorbic acid, sorbicacid, α-chlorsorbic acid, cinnamic acid, and hydromuconic acid as wellas esters of such acids. Examples of vinyl aromatic hydrocarbons includestyrene, methyl styrenes and similar lower alkyl styrenes,chlorostyrene, vinyl toluene, vinyl naphthalene, and divinyl benzoate.Vinyl aliphatic hydrocarbon monomers include α-olefins such as ethylene,propylene, isobutylene, and cyclohexene as well as conjugated dienessuch as 1,3-butadiene, methyl-2-butadiene, 1,3-piperylene, 2,3 dimethylbutadiene, isoprene, cyclopentadiene, and dicyclopentadiene. Somerepresentative examples of vinyl esters include vinyl acetate, vinylpropionate, vinyl butyrates, vinyl benzoates, vinyl isopropyl acetatesand similar vinyl esters. Vinyl alkyl ethers include methyl vinyl ether,isopropyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether.

Acrylic monomers include monomers such as lower alkyl esters of acrylicor methacrylic acid having an alkyl ester portion containing between 1to 12 carbon atoms as well as aromatic derivatives of acrylic andmethacrylic acid. Useful acrylic monomers include, for example, acrylicand methacrylic acid, methyl acrylate and methacrylate, ethyl acrylateand methacrylate, butyl acrylate and methacrylate, propyl acrylate andmethacrylate, 2-ethyl hexyl acrylate and methacrylate, cyclohexylacrylate and methacrylate, decyl acrylate and methacrylate,isodecylacrylate and methacrylate, benzyl acrylate and methacrylate, andvarious reaction products such as butyl, phenyl an cresyl glycidylethers reacted with acrylic and methacrylic acids, hydroxyl alkylacrylates and methacrylate such as hydroxyethyl and hydroxypropylacrylates and methacrylates, as well as amino acrylates andmethacrylates. Acrylic acids include acrylic and methacrylic acid,ethacrylic acid, α-chloracrylic acid, α-cycanoacrylic acid, crotonicacid, β-acryloxy propionic acid, and β-styrlacrylic acid. Examples ofacrylamide monomers include, but are not limited to, acrylamides ormethacrylamides such as N-methylol acrylamide, N-ethanol acrylamide,N-propanol acrylamide, N-methylol methacrylamide, N-ethanolmethacrylamide, and similar alkyl acrylamide or methacrylamide monomerscontaining methyl, ethyl, propyl, n-butyl or iso-butyl alkyl groups. Inone embodiment, for example, the ethylenically unsaturated monomers ofthe acrylic copolymer (B) are chosen from at least one of acrylate,methacrylate, styrene, (meth)acrylic acid, and vinyl esters.

As noted above, the acrylic copolymer comprises at least one hydroxyl,epoxy, carboxyl, blocked phenol, or acetoacetoxy functional groupobtained by copolymerizing ethylenically unsaturated monomers with otheracrylate monomers such as methyl acrylate, methyl methacrylate, ethylacrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate,isobutyl acrylate, isobutyl methacrylate, ethylhexyl acrylate,ethylhexyl methacrylate. Examples of carboxy containing monomers includeacrylic acid and lower alkyl substituted acrylic acids such as forexample, methacrylic acids. Examples of hydroxyl containing monomersinclude ethylenically unsaturated monomers such as, for example,hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxyhexyl acrylate,hydroxyhexyl methacrylate, hydroxypropyl acrylate, hydroxypropylmethacrylate, hydroxybutyl acrylate, hydroxylbutyl methacrylate and thelike. The ratio of reagents and molecular weights of the resultingacrylic polymer can be chosen to give polymers with an averagefunctionality (for example, the number of OH groups per molecule)greater than or equal to 2 or, in another example, greater than or equalto 4.

The acrylic copolymer may be prepared according to procedures well-knownto persons having ordinary skill in the art or can be purchasedcommercially. For example, commercially available hydroxyl-functionalacrylic resins include the MACRYNAL™ series, available from CytecSurface Specialties, the ACRYLOID™ series, available from Rohm and HaasCompany, and the JONCRYL™ series, available from BASF Corporation.

The curable polyester and the acrylic copolymer, typically, are blendedtogether. The weight percent of polyester in the blend is about 2 toabout 50 weight percent, based on the total weight of the polyester andacrylic copolymer. Other examples of the amount of polyester in thepolyester/acrylic blend are about 5 to about 40 weight percent, and mostpreferably about 8 to about 30 weight percent. Our thermosetting coatingcomposition may further comprise about 10 to about 50 weight percent ofat least one crosslinker based on the total weight of the curablepolyester, the acrylic copolymer, and the crosslinker (components (A),(B), and (C) above). Typically, the crosslinker will be a compound thatcan react with either the carboxylic acid-terminated orhydroxyl-terminated curable polyester and blends with the acryliccopolymer. For example, crosslinker can comprise at least one compoundchosen from epoxides, melamines, hydroxy alkyl amides, isocyanates, andisocyanurates. These crosslinkers and their application to coatings aregenerally known in the art. For example, epoxide crosslinkers will reactwith a carboxylic acid-terminated polyester or carboxyl functionalacrylic copolymer, whereas melamines, isocyanates, isocyanurates willreact with a hydroxyl-terminated polyesters and hydroxyl-functionalacrylic copolymers.

Epoxide crosslinkers can include, but are not limited to, at least oneepoxide compound chosen from epoxy resins comprising bisphenol A, epoxynovolac resins, epoxy resins containing hydrogenated bisphenol A, epoxyresins containing bisphenol F, triglycidylisocyanurate, and combinationsof these crosslinkers. Some examples of commercially available epoxidecrosslinkers include those epoxides sold under the EPON™ trademark,available from Hexion Specialty Chemicals, and those sold under theARALDITE™ trademark, available from Huntsman Advanced Materials.

Melamine or “amino” type crosslinkers also are well-known in the art andcan be used in the present invention. Thus, for example, the coatingcomposition of the present invention can comprise at least one melaminecompound chosen from hexamethoxymethylmelamine,tetramethoxymethylbenzoguanamine, tetramethoxymethylurea, and mixedbutoxy/methoxy substituted melamines. Examples of commercially availablemelamine crosslinkers include the CYMEL™300 series and CYMEL™ 1100series melamine crosslinkers, available from Cytec Surface Specialties.

In addition to epoxides and melamines, isocyanates and isocyanurates canbe used as crosslinkers in accordance with the invention. Representativeisocyanates and isocyanurates include, but are not limited to, at leastone compound chosen from toluene diisocyanate, isocyanurates of toluenediisocyanate, diphenylmethane 4,4′-diisocyanate, isocyanurates of4,4′-diisocyanate, methylenebis-4,4′-isocyanatocyclohexane, isophoronediisocyanate, isocyanurates of isophorone diisocyanate, the biuret of1,6-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate,isocyanurates of 1,6-hexamethylene diisocyanate, 1,4-cyclohexanediisocyanate, p-phenylene diisocyanate, and triphenylmethane4,4′,4″-triisocyanate, tetramethyl xylene diisocyanate, metaxylenediisocyanate, polyisocyanates, 1,4-butylene diisocyanate, methylenebis(4-cyclohexyl isocyanate), isophorone diisocyanate andisocyanate-terminated adducts of ethylene glycol, 1,4-butylene glycol,and trimethylol propane.

The coating composition can also comprise isocyanate-terminated adductsof diols and polyols, such as ethylene glycol, 1,4-butylene glycol,trimethylol propane, etc., as crosslinkers. These crosslinkers areformed by reacting more than one mole of a diisocyanate, such as thosementioned above, with one mole of a diol or polyol to form a highermolecular weight isocyanate prepolymer with a functionality of 2 to 3.Some commercial examples of isocyanate-terminated adducts includeisocyanate crosslinkers under the DESMODUR™ and MONDUR™ trademarksavailable from Bayer Material Science.

In one embodiment of the invention, the crosslinker comprises at leastone aliphatic isocyanate, which can provide good outdoor durability andcolor stability in the cured coating. Examples of aliphatic isocyanatesinclude 1,6-hexamethylene diisocyanate, 1,4-butylene diisocyanate,methylene bis(4-cyclohexyl isocyanate), isophorone diisocyanate, andcombinations thereof. Mixtures of isocyanate crosslinkers can also beemployed. In another embodiment, the crosslinker can comprise theisocyanurates of 1,6-hexamethylene diisocyanate, the biuret of1,6-hexamethylene diisocyanate, or a mixture thereof. In yet anotherembodiment, the crosslinker can comprise the trimer of 1,6-hexamethylenediisocyanate. Stoichiometric calculations for the curable polyester andisocyanate reaction are known to those skilled in the art and aredescribed in The Chemistry of Polyurethane Coatings, TechnicalPublication p. 20, by Bayer Material Science, 2005. Persons havingordinary skill in the art will understand that crosslinking between thepolyester resin and isocyanate reaches maximum molecular weight andoptimal properties associated with molecular weight at anisocyanate:hydroxyl ratio of about 1:1; that is, when one equivalent ofisocyanate (—NCO) reacts with one equivalent of hydroxyl (—OH).Typically, however, a small excess of isocyanate, about 5-10%, is usedto allow for the loss of isocyanate by the reaction with adventitiousmoisture from the atmosphere, solvents, and pigments. Other NCO:OHratios can be used; for example, it may be desirable to vary the NCO toOH ratio to less than 1:1 to improve flexibility or greater than 1:1 toproduce harder, more chemical resistant, and more weather resistantcoatings.

The coating composition of the present invention typically has an NCO:OHratio of about 0.9:1.0 to about 1.5:1.0. Examples of other NCO:OH ratiosare about 0.95:1.0 to about 1.25:1.0 and about 0.95:1.0 to about1.1:1.0.

The coating composition also comprises about 10 to about 60 weightpercent of at least one solvent, based on the total weight of thecurable polyester, acrylic copolymer, crosslinker, and the solvent(components (A), (B), (C), and (D)). Examples of solvents include, butare not limited to, benzene, xylene, mineral spirits, naphtha, toluene,acetone, methyl ethyl ketone, methyl n-amyl ketone, methyl isoamylketone, n-butyl acetate, isobutyl acetate, t-butyl acetate, n-propylacetate, isopropyl acetate, ethyl acetate, methyl acetate, ethanol,n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, ethyleneglycol monobutyl ether, propylene glycol n-butyl ether, propylene glycolmethyl ether, propylene glycol monopropyl ether, dipropylene glycolmethyl ether, diethylene glycol monobutyl ether, trimethyl-pentanediolmono-isobutyrate, ethylene glycol mono-octyl ether, diacetone alcohol,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (available commerciallyfrom Eastman Chemical Co. under the trademark TEXANOL™), or combinationsthereof. The coating compositions may also comprise reactive solventssuch as, for example, diallyl phthalate, SANTOLINK™ XI-100 polyglycidylallyl ether (available from Cytec Surface Specialties), and others asdescribed, for example, in U.S. Pat. Nos. 5,349,026 and 5,371,148.Typically, the coating composition of this invention will comprise about40 to about 90 weight percent solids (i.e., non-volatiles), based on thetotal weight of the coating composition. Some additional examples ofweight percent solids for the coating composition of the invention are50, 60, 65, 70, 75, 80, and 85 weight percent.

The coating compositions of the invention, optionally, can furthercomprise at least one crosslinking catalyst. Representative crosslinkingcatalysts include carboxylic acids, sulfonic acids, tertiary amines,tertiary phosphines, tin compounds, or combinations of these compounds.Some specific examples of crosslinking catalysts are one or morecompounds chosen from p-toluenesulfonic acid, dodecylbenzene sulfonicacid, dinonylnaphthalene sulfonic acid, and dinonylnaphthalenedisulfonic acid, benzoic acid, triphenylphosphine, dibutyltindilaurate,and dibutyltindiacetate. The crosslinking catalyst can depend on thetype of crosslinker that is used in the coating composition. Forexample, the crosslinker can comprise an epoxide, and the crosslinkingcatalyst can comprise at least compound chosen from p-toluenesulfonicacid, benzoic acid, tertiary amines, and triphenylphosphine. In anotherexample, the crosslinker can comprise a melamine or “amino” crosslinkerand the crosslinking catalyst can comprise p-toluenesulfonic acid,unblocked and blocked dodecylbenzene sulfonic (abbreviated herein as“DDBSA”), dinonylnaphthalene sulfonic acid (abbreviated herein as“DNNSA”) and dinonylnaphthalene disulfonic acid (abbreviated herein as“DNNDSA”). Some of these catalysts are available commercially under thetrademarks such as, for example, NACURE™ 155, 5076, 1051, and 5225(available from King Industries), and BYK-CATALYSTS™ (available fromBYK-Chemie USA).

In another embodiment, the curable polyester can comprisehydroxyl-terminated end and the crosslinker can comprise an isocyanates.Examples of isocyanate crosslinking catalysts include FASCAT™ 4202(dibutyltindilaurate), FASCAT™ 4200 (dibutyltindiacetate, both availablefrom Arkema), DABCO™ T-12 (available from Air Products) and K-KAT™ 348,4205, 5218, XC-6212™ non-tin catalysts (available from King Industries),and tertiary amines.

In another example, the thermosetting coating composition can compriseabout 25 to about 35 weight percent solvent, about 20 to about 35 weightpercent of a melamine crosslinker, and a crosslinking catalystcomprising p-toluenesulfonic acid. In yet another example, thethermosetting coating composition comprises about 25 to about 35 weightpercent solvent, and about 20 to about 35 weight percenthexamethoxymethylmelamine.

The thermosetting coating composition of this invention may furthercontain one or more coating additives known in the art. Examples ofsuitable coating additives include, but are not limited to, at least oneof leveling, rheology and flow control agents such as silicones,fluorocarbons or cellulosics; extenders; plasticizers; flatting agents;pigment wetting and dispersing agents; ultraviolet (UV) absorbers; UVlight stabilizers; defoaming and antifoaming agents; anti-settling,anti-sag and bodying agents; anti-skinning agents; anti-flooding andanti-floating agents; and corrosion inhibitors. Specific examples ofsuch additives can be found in the Raw Material Index and Buyer's Guide,published by the National Paint & Coatings Association, 1500 RhodeIsland Avenue, N.W., Washington., DC 20005. Some additional examples ofsuch additives may be found in U.S. Pat. No. 5,371,148.

Examples of flatting agents include, but are not limited to, syntheticsilica, available from the Davison Chemical Division of W. R. Grace &Company as SYLOID™; polypropylene, available from Hercules Inc., asHERCOFLAT™; and synthetic silicate, available from J. M. HuberCorporation, as ZEOLEX™.

Examples of dispersing agents include, but are not limited to, sodiumbis(tridecyl) sulfosuccinate, di(2-ethyl hexyl) sodium sulfosuccinate,sodium dihexylsulfosuccinate, sodium dicyclohexyl sulfosuccinate, diamylsodium sulfosuccinate, sodium dusobutyl sulfosuccinate, disodiumiso-decyl sulfosuccinate, disodium ethoxylated alcohol half ester ofsulfosuccinic acid, disodium alkyl amido polyethoxy sulfosuccinate,tetra-sodium N-(1,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate,disodium N-octasulfosuccinamate, sulfated ethoxylated nonylphenol,2-amino-2-methyl-1-propanol, and the like.

Examples of viscosity, suspension, and flow control agents include, butare not limited to, polyaminoamide phosphate, high molecular weightcarboxylic acid salts of polyamine amides, and alkylene amine salts ofan unsaturated fatty acid, all available from BYK Chemie USA as ANTITERRA™. Further examples include, but are not limited to, polysiloxanecopolymers, polyacrylate solution, cellulose esters, hydroxyethylcellulose, hydroxypropyl cellulose, polyamide wax, polyolefin wax,hydroxypropyl methyl cellulose, polyethylene oxide, and the like. Forexample, the thermosetting composition can contain BYK 331, availablefrom BYK-Chemie, as a flow and leveling additive.

Several proprietary antifoaming agents are commercially available andinclude, but are not limited to, BUBREAK™ of Buckman Laboratories Inc.,BYK™ of BYK Chemie, U.S.A., FOAMASTER™ and NOPCO™ of HenkelCorp./Coating Chemicals, DREWPLUS™ of the Drew Industrial Division ofAshland Chemical Company, TROYSOL™ and TROYKYD™ of Troy ChemicalCorporation, and SAG™ of Union Carbide Corporation.

Examples of UV absorbers, UV light stabilizers, and antioxidantsinclude, but are not limited to, substituted benzophenone, substitutedbenzotriazoles, hindered amines, hindered benzoates, phenols, andphosphites, some of which are available from Cytec Specialty Chemicalsas CYASORB® UV, and from Ciba Specialty Chemicals as TINUVIN®,CHIMASSORB®, IRGANOX® and IRGAFOS®; anddiethyl-3-acetyl-4-hydroxy-benzyl-phosphonate, 4-dodecyloxy-2-hydroxybenzophenone, and resorcinol monobenzoate. For example, in oneembodiment, the thermosetting coating composition can contain IRGANOX®1010 antioxidant, available from Ciba Specialty Chemicals.

The paint or coating additives described above generally form arelatively minor proportion of the coating composition, typically about0.05 weight percent to about 5.00 weight percent. Although thethermosetting coating compositions of the present invention areprimarily intended as non-pigmented clear coats, they may optionallycontain one or more pigments in addition to the above-describedadditives.

For example, an additional aspect of the invention includes solventborne thermosetting coating compositions that contain one or morepigments. Typical levels of pigment can be about 20 to about 60 weightpercent, based on the total weight of the composition. Examples ofsuitable pigments include those recognized by those of ordinary skill inthe art of surface coatings. For example, the pigment may be a typicalorganic or inorganic pigment, especially those set forth by the ColourIndex, 3rd ed., 2nd Rev., 1982, published by the Society of Dyers andColourists in association with the American Association of TextileChemists and Colorists. Other examples of suitable pigments include, butare not limited to, titanium dioxide, barytes, clay, calcium carbonate,CI Pigment White 6 (titanium dioxide), CI Pigment Red 101 (red ironoxide), CI Pigment Yellow 42, CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4(copper phthalocyanines); CI Pigment Red 49:1 and CI Pigment Red 57:1.Colorants such as, for example, phthalocyanine blue, molybdate orange,or carbon black also may be added to the coating composition.

The thermosetting coating composition can be applied to any commonsubstrate such as paper; polymer films such as polyethylene orpolypropylene; wood; metals such as aluminum, steel or galvanizedsheeting; glass; urethane elastomers, primed (painted) substrates; andthe like. The coating composition can be coated onto a substrate usingtechniques known in the art; e.g. by spraying, draw-down, roll-coating,etc. 0.5 to 4 mils of wet coating onto a substrate. The coating can becured at ambient (room) temperature or heated in a forced air oven to atemperature of about 50° C. to about 175° C., for a time period of 5-120minutes and subsequently allowed to cool. Thus, a further aspect of thepresent invention, is a shaped or formed article that has been coatedwith the coating compositions of the present invention and cured.Further representative examples of typical application and curingmethods can be found in U.S. Pat. Nos. 4,737,551 and 4,698,391 and3,345,313.

A further aspect of the present invention is a thermosetting coatingcomposition, consisting essentially of:

-   (A). about 2 to about 50 weight percent, based on the total weight    of (A), (B), and (C) of a curable polyester, consisting essentially    of:    -   i. diacid residues, consisting essentially of about 20 to 100        mole percent, based on the total moles of diacid residues, of        the residues of isophthalic acid;    -   ii. diol residues, consisting essentially of about 20 to 100        mole percent, based on the total moles of diol residues, of the        residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about        80 to about 0 mole percent of the residues of neopentyl glycol;        and    -   iii. about 2 to about 40 mole percent of the residues of at        least one polyol chosen from trimethylolpropane,        pentaerythritol, trimethylolethane, erythritol, and        dipentaerythritol;    -   wherein the curable polyester has a number average molecular        weight of about 500 to about 10,000 daltons, a glass transition        temperature of about −35° C. to about 80° C., a hydroxyl number        of about 20 to about 300 mg KOH/g of polyester, and an acid        number of 0 to about 80 mg KOH/g of polyester;-   (B). about 25 to about 88 weight percent, based on the total weight    of (A), (B), and (C) of at least one acrylic copolymer of    ethylenically unsaturated monomers comprising at least one hydroxyl,    epoxy, carboxyl, blocked phenol, or acetoacetoxy functional group;-   (C). about 10 to about 50 weight percent, based on the total weight    of (A), (B), and (C), of at least one crosslinker chosen from    epoxides, melamines, isocyanates, and isocyanurates;-   (D). about 10 to about 60 weight percent, based on the total weight    of (A), (B), (C), and (D) of at least one solvent;-   (E). a crosslinking catalyst comprising at least one compound chosen    from p-toluenesulfonic acid, dodecylbenzene sulfonic acid,    dinonylnaphthalene sulfonic acid, and dinonylnaphthalene disulfonic    acid, benzoic acid, triphenylphosphine, dibutyltindilaurate, and    dibutyltindiacetate; and-   (F). at least one coating additive chosen from leveling agents,    rheology agents, flow control agents, plasticizers, flatting agents,    pigment wetting and dispersing agents, pigments, dyes, ultraviolet    light absorbers, ultraviolet light stabilizers; defoaming agents,    antifoaming agents, anti-settling agents, anti-sag agents, bodying    agents, anti-skinning agents; anti-flooding agents, anti-floating    agents, and corrosion inhibitors.    The above thermosetting coating composition is understood to include    the various embodiments of the curable polyester, acrylic copolymer,    crosslinker, solvent, crosslinking catalyst and coating additives    described previously. The phrase “consisting essentially of”, as    used herein, is intended to encompass thermosetting coating    compositions having components (A)-(F) listed above and is    understood to exclude any elements that would substantially alter    the essential properties of the composition to which the phrase    refers. For example, compositions may include other components that    do not alter the haze or miscibility of the curable polyester,    acrylic copolymer, and solvent. For example, the addition of an    additional diol or diacid component, which may alter this    miscibility, would be excluded from this embodiment. For example,    the addition of 50 mole percent or greater of the residues of a diol    or diacid that is known in the art to increase the crystallinity and    reduce the miscibility of a polyester polymer would be excluded from    this embodiment. Some representative classes of diacids and diols    that would be expected to increase crystallinity and reduce    miscibility include, but are not limited to, para-substituted    aromatic diol or diacid components, multinuclear aromatic diacids or    diols, and alicyclic diols and diacids in which the diol and diacid    groups have a 1,4 substitution pattern or a “para” relationships to    each other. Some examples of diacid and diol components that would    be excluded from this embodiment are the residues of terephthalic    acid at 50 mole percent or greater, 1,6-naphthalene dicarboxylic    acid at 50 mole percent or greater, 1,4-cyclohexane-dicarboxylic    acid at 75 mole percent or greater, bisphenol A at 50 mole percent    or greater, 1,4-cyclohexanedimethanol at 75 mole percent or greater,    and hydrogenated bisphenol A at 50 mole percent or greater. All mole    percentages are based upon the total moles of diacid or diol    residues.

By contrast, some examples of compositions that would be included in theabove embodiment are those, for example, wherein the diacid componentconsists essentially of about 20 to about 80 mole percent of isophthalicacid and about 80 to about 20 mole percent of adipic acid, and the diolcomponent consists essentially of about 20 to 100 mole percent2,2,4,4-tetramethyl-1,3-cyclobutanediol. In another example, the diacidcomponent can consist essentially of about 30 to about 70 mole percentof the residues of isophthalic acid and about 70 to about 30 molepercent of the residues of adipic acid, and the diol component consistsessentially of about 20 to 100 mole percent2,2,4,4-tetramethyl-1,3-cyclobutanediol. In another example, the diacidcomponent can consist essentially of about 40 to about 60 mole percentof the residues of isophthalic acid and about 60 to about 40 molepercent of the residues of adipic acid. As described previously, thediacid component may further consist essentially of up to 30 molepercent of the residues at least one diacid chosen from phthalic acid,terephthalic acid, tetrachlorophthalic acid, dodecanedioic acid, sebacicacid, azelaic acid, 1,4-cyclohexanedicarboxylic acid,1,3-cyclohexanedicarboxylic acid, hexahydrophthalic acid,tetrahydrophthalic acid, maleic acid, fumaric acid, succinic acid,2,6-naphthalenedicarboxylic acid, and glutaric acid. In another example,the coating composition can consist essentially of about 50 to about 100mole percent of the residues of isophthalic acid, 0 to about 50 molepercent of the residues of adipic acid, about 100 mole percent of theresidues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 10 molepercent of the residues of trimethylolpropane, wherein the curablepolyester has a hydroxyl number of about 30 to about 250 mg potassiumhydroxide per gram of polyester, an acid number of about 2 to about 15mg potassium hydroxide per gram of polyester, a Tg of about −20 to about50° C., and a number average molecular weight of about 700 to about 7000daltons.

In addition to 2,2,4,4-tetramethyl-1,3-cyclobutanediol, the diolcomponent can consist essentially of up to 50 mole percent of theresidues of at least one diol chosen from neopentyl glycol, ethyleneglycol, propylene glycol, diethylene glycol, triethylene glycol,tetraethylene glycol, pentaethylene glycol, hexaethylene glycol,heptaethylene glycol, octaethylene glycol, nonaethylene glycol,decaethylene glycol, 1,3-propanediol,2,4-dimethyl-2-ethyl-hexane-1,3-diol, 2,2-dimethyl-1,2-propanediol,2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol,1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,2,2,4-tetramethyl-1,6-hexanediol, thiodiethanol,1,2-cyclohexane-dimethanol, 1,3-cyclohexanedimethanol,1,4-cyclohexanedimethanol, 2,2,4-trimethyl 1,3-pentanediol,p-xylenediol, hydroxypivalyl hydroxypivalate, 1,10-decanediol, andhydrogenated bisphenol A.

As described previously, the coating composition comprises a non-aqueoussolvent (D), which can comprise at least one organic liquid chosen frombenzene, xylene, mineral spirits, naphtha, toluene, acetone, methylethyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, n-butylacetate, isobutyl acetate, t-butyl acetate, n-propyl acetate, isopropylacetate, ethyl acetate, methyl acetate, ethanol, n-propanol,isopropanol, n-butanol, sec-butanol, isobutanol, ethylene glycolmonobutyl ether, propylene glycol n-butyl ether, propylene glycol methylether, propylene glycol monopropyl ether, dipropylene glycol methylether, diethylene glycol monobutyl ether, trimethylpentanediolmono-isobutyrate, ethylene glycol mono-octyl ether, diacetone alcohol,and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate. The invention isfurther illustrated by the following examples.

EXAMPLES

Preparation of Comparative Example Polyester Resins and ResultingProperties—

Comparative example polyester resin 1 (indicated as “CE1” in Table 1)was prepared according to the following procedure, targeting a numberaverage molecular weight=2500 daltons and a final acid number=10. Theresin was made using conventional fusion processing methods. The resinwas prepared in a two-liter reaction kettle equipped with a heatingmantle, mechanical stirrer, thermocouple, nitrogen blanket (0.4 scfh),oil-heated partial condenser (103° C.-105° C.), condensate trap, andwater-cooled total condenser (15° C.). The kettle top and adapter fromthe kettle to the column were wrapped in aluminum foil to facilitatewater removal. The neopentyl glycol (“NPG”) and trimethylolpropane(“TMP”) were charged to the reactor and heated from room temperature to150° C. over sixty minutes to form a homogenous melt. Agitation (300rpm) was then started, and the isophthalic acid and catalyst werecharged and thoroughly mixed to form a slurry. The temperature wasincreased from 150° C. to 180° C. over 15 minutes, then heated to 235°C. over 360 minutes. The reaction mixture was held at 235° C. until afinal acid number of 9±2 mg KOH/g resin was obtained. The resin was thenpoured into a metal paint can.

Comparative polyester resin examples 2, 3 and 4 (CE2, CE3 and CE4 inTable 1) were prepared according to the following procedure, targeting anumber average molecular weight=1250, a hydroxyl equivalent weight=500 gresin/eq OH, a hydroxyl functionality=2.5 and final acid number=8. Theresins were made using a solvent process to help remove the water ofesterification. The resins were prepared in a two-liter reaction kettleequipped with a heating mantle, mechanical stirrer, thermocouple,nitrogen blanket (0.6 scfh), oil-heated partial condenser (103° C.-105°C.), condensate trap, and water-cooled total condenser (15° C.). Thecondensate trap, kettle top and adapter from the kettle to the columnwere wrapped in aluminum foil and fiberglass tape to facilitate waterremoval. Stage 1 raw materials were charged to the reactor. Additionalxylene (approx. 30 g) was used to fill the moisture trap. Thetemperature was then increased from room temperature to 150° C. overninety minutes to form a homogenous melt. Agitation (300 rpm) wasstarted and the temperature increased to 230° C. over 240 minutes. TheStage 2 TMP was added when half the theoretical condensate wascollected. The reaction mixture was held at 230° C. until a final acidnumber of 6±2 mg KOH/g resin was obtained. The resin was then pouredinto a metal paint can.

The acid number, number average molecular weight (“Mn”), and glasstransition temperature (“Tg”) of each resin were determined and areshown in Tables 1 and 2. Acid number was determined using ASTM method1639. Hydroxyl number was determined by esterifying the resin byreaction with excess acetic anhydride in pyridine and then decomposingthe unreacted anhydride with water. The resulting acetic acid is thentitrated with a standard solution of KOH. The milligrams KOH required toneutralize the acetic acid released from one gram of resin sample in theabove procedure is reported as the hydroxyl number. Number averagemolecular weight was determined by gel permeation chromatography(Agilent 1100 Series GPC-SEC system) with a refractive index detectorand polystyrene standards.

The Tg of comparative example polyester resin CE1 was determined using adifferential scanning calorimeter (Mettler Toledo 821 DSC). The samplewas scanned under nitrogen purge from −20° C. to 160° C. on the firstheat cycle, cooled from melt, and subjected to a second heat from −20°C. to 160° C. The heating and cooling rate was 20° C./min. The midpointof the second heat cycle is reported as the Tg of the sample.

For comparative example polyester resins CE2, CE3 and CE4, the Tg of theresin the above procedure was modified to remove residual xyleneremaining from solvent processing that could artificially lower the Tgmeasurement. To obtain a more accurate Tg, a resin sample was firstsubjected to preconditioning in a thermal gravimetric analysis (“TGA”)instrument. The resin sample was placed into a stainless steeldifferential scanning calorimeter (“DSC”) pan and heated under nitrogenatmosphere from room temperature to 150° C. at a rate of 5° C./min. Thesample was then transferred to a differential scanning calorimeter withmodulating capability (TA Instruments Q2000 MDSC with Universal softwareV4.3A). On the first heating cycle, the sample was heated under nitrogenatmosphere from −120° C. to 125° C. at a rate of 5° C./min and amodulation rate of ±0.796° C./min. Next, it was cooled to −120° C. at 5°C./min and a modulation rate of ±0.796° C./min. For the second heatingcycle, the sample was heated under the same conditions as those used inthe first heating cycle. The midpoint of the second heating cycle isreported as the Tg of the sample.

TABLE 1 Comparative Example Polyester Resin Formulations (Grams) andDetermined Resin Properties Example CE1 CE2 CE3 CE4 Charge Weights Stage1 NPG(a) 658.00 422.76(b) 429.74(b) 440.11(b) TMP(c) 44.03 35.93 35.9936.35 IPA(d) 1029.02 647.26 526.82 338.11 AD(e) — — 115.85 297.41 Fascat4100 1.50 1.14 1.14 1.14 catalyst(f) Xylene process — 22.75 22.8 22.88solvent Stage 2 TMP — 35.93 35.99 36.35 Total Charge 1719.67 1165.771168.33 1172.35 Minus Theo. 218.17 137.70 140.13 143.97 Condensate Yield1501.50 1028.07 1028.20 1028.38 Determined Resin Properties AN (mg 7 6 65 KOH/g resin) OH# (mg 39 106 105 102 KOH/g resin) Mn (daltons) 30981988 2033 1906 Tg (° C.) 55.6 36.8 14.5 −14.0(a)2,2-Dimethyl-1,3-propanediol (Eastman). (b)Includes a glycol excessof 1 wt. % based on calculated charge weights. (c)Trimethylolpropane(Perstorp). (d)Isophthalic acid (Eastman). (e)Adipic acid (DuPont).(f)Butylstannoic acid (Arkema).

Preparation of Polyester Resins and Resulting Properties—

Example polyester resin formulations E5 through E9 were prepared using asolvent process and the same target resin properties as described forcomparative example polyester resins CE2, CE3 and CE4, and are set forthin Table 2. Example polyester resin formulation E10 was prepared using afusion process and the same target resin properties as described forcomparative example polyester resin CE1. Resin properties weredetermined in the same manner as described for the comparative examplepolyester resins and shown in Table 2.

TABLE 2 Example Polyester Resin Formulations (Grams) and DeterminedResin Properties Example E5 E6 E7 E8 E9 E10 Charge Weights Stage 1NPG(a) 313.31(b) 199.64(b) 96.02(b) — — 304.70 TMCD(c) 144.61(b)276.42(b) 398.84(b) 511.18(b) 500.89(b) 421.40 TMP(d) 36.05 36.73 36.4636.64 36.36 40.51 IPA(e) 323.2 309.72 297.09 285.55 446.58 948.28 AD(f)284.29 272.43 261.32 251.18 98.21 — Fascat 4100 catalyst(g) 1.14 1.131.13 1.12 1.12 1.50 Xylene process solvent 22.75 22.63 22.52 22.42 22.37— Stage 2 TMP 36.05 36.73 36.46 36.64 36.36 — Total Charge 1165.981160.19 1154.79 1149.84 1146.9 1702.18 Minus Theo. Condensate 137.5131.67 126.19 121.19 118.41 200.68 Yield 1028.48 1028.52 1028.6 1028.651028.49 1501.50 Determined Resin Properties AN (mg KOH/g resin) 5 5 4 55 11 OH# (mgKOH/g resin) 97 98 93 89 93 30 Mn (daltons) 2046 2113 21382208 2416 3772 Tg (° C.) −8.0 −1.5 5.9 14.1 43.8 78.0(a)2,2-Dimethyl-1,3-propanediol (Eastman). (b)Includes a glycol excessof 1 wt. % based on calculated charge weights.(c)2,2,4,4-Tetramethyl-1,3-cyclobutanediol (Eastman).(d)Trimethylolpropane (Perstorp). (e)Isophthalic acid (Eastman).(f)Adipic acid (DuPont). (g)Butylstannoic acid (Arkema).

Compatibility of Polyester/Acrylic Blends—

The polyester resins were evaluated for compatibility with acommercially available acrylic resin, MACRYNAL™ SM 515/70BAC (availablefrom Cytec Surface Specialties). MACRYNAL™ SM 515 is a hydroxyfunctional acrylic resin that is crosslinkable with aliphaticpolyisocyanates, and is suggested by its manufacturer for use inair-drying and forced drying, two pack high solids automotive refinishcoatings.

SETAL™ 1603 BA-78 (available from Nuplex Resins) is a commerciallyavailable polyester resin with good drying properties and goodthrough-hardening and high hardness in combination with aliphaticpolyisocyanates. It is suggested by its manufacturer for use as aco-binder in combination with acrylic resins in two pack high solidsclearcoats and solid color topcoats for vehicle refinishes. The acrylicin combination with SETAL™ 1603 serves as an additional comparativeexample using commercial materials representing current availabletechnology.

A 1:1 blend of polyester and acrylic resins was evaluated at 60 weight %solids in n-butyl acetate. All of the polyester resins were reduced to70 weight % solids in n-butyl acetate. SETAL™ 1603 is supplied as a 78weight % solids solution in n-butyl acetate. Additional n-butyl acetatewas required to reduce the resin solids to 70 weight %. MACRYNAL™ SM 515is supplied as a 70 weight % solution in n-butyl acetate. To a 4 oz. jarwas added 40.0 g of each 70 weight % solids resin solution. Another 13.3g of n-butyl acetate was then added to make 93.3 g of a 60 weight %solids blend of the resins. The solutions were rolled at roomtemperature for about 24 hours to mix the components. Some samplesrequired additional rolling in a steam cabinet at 71° C. (160° F.) tointimately mix the blends. A portion of each polyester/acrylic blend wascast as a 10 mil wet film onto glass and allowed to dry in an oven for60 min. at 52° C. (125° F.) followed by room temperature drying for 7days before evaluation.

The compatibility of the polyesters with the acrylic resin wasdetermined by evaluating the solutions with a visual inspection and thedry films by visual inspection and percent haze as measured with aBYK-Gardner haze-gard plus instrument using ASTM method D 1003, MethodA, and are shown in Table 3.

TABLE 3 Compatibility of Polyester/Acrylic Resin Blends Com- PE/ASolution Clarity Film Clarity patible? Blend Example Visual Visual %(Yes/ Example Polyester Appearance Appearance Haze No) CE11 CE1 opaque,white hazy 99.80 no solid CE12 CE2 opaque, white hazy 99.10 no solidCE13 CE3 opaque, white hazy 74.93 no solid CE14 CE4 clear solution clear0.45 yes CE15 SETAL clear solution clear 0.30 yes 1603 E16 E5 clearsolution clear 0.32 yes E17 E6 clear solution clear 0.40 yes E18 E7clear solution clear 0.30 yes E19 E8 clear solution clear 0.25 yes E20E9 clear solution clear 7.31 yes E21 E10 clear solution clear 0.71 yes

Comparative example blend CE11 contains a higher molecular weightpolyester resin with NPG and 100 mole percent isophthalic acid.Similarly, comparative example blend CE12 contains a lower molecularweight polyester resin with NPG and 100 mole percent IPA content. Bothexhibit poor compatibility with the acrylic resin.

In comparative example blends CE13 and CE14, 20 and 50 mole % of theisophthalic acid in the polyester formulation is substituted with adipicacid (“AD”), respectively. Only when the AD level reaches 50 mole % ofthe diacid component is the NPG polyester compatible with the acrylicresin. As suggested in Nuplex technical literature, the SETAL™ 1603 iscompatible with the acrylic resin in comparative example blend CE15.

In examples E16 through E19, the blends contain polyester resinsincreasing in TMCD content with a constant diacid component of 50:50molar IPA/AD. All of these polyesters exhibit good compatibility withthe acrylic resin.

Example blend E20 contains a TMCD polyester resin with an 80:20 molarratio of IPA/AD. Unlike the polyester resin in comparative example blendCE13, this polyester exhibits good compatibility with the acrylic resin.

Example blend E21 contains a high molecular weight polyester resinhaving a 50:50 molar ratio of NPG:TMCD with all IPA as the diacidcomponent (high aromatic acid content). Unlike the polyester incomparative example blend CE11, this polyester is compatible with theacrylic resin.

Clear coat Formulations, Dry Time, Sag Resistance and HardnessDevelopment—

Clear polyurethane coatings were prepared and are shown in Table 4. Theresins were crosslinked with a 1,6-hexamethylene diisocyanate trimer(Rhodia TOLONATE™ HDT-LV) at a 1.1:1 NCO:OH ratio.

The drying process of a thin film in an open air environment, such as anautomotive refinish clear coat, was simulated using an AdvancedRheometrics Expansion System (“ARES”) rheometer (available from TAInstruments). This rheological technique used to determine dryingbehavior as a function of time is described in detail in the Proceedingsof the International Waterborne, High-Solids, and Powder CoatingsSymposium (2004), 31st 221-36, by K. S. Seo, et al. The clear coatformulations in Table 4 were scaled back to one tenth of the amountslisted. Part A components were added to a 4 oz. glass jar and rolled forabout 24 hrs. The Part B crosslinker was then added and mixed on a highspeed roller for 5 min. A 1-mL Monoject tuberculin syringe (availablefrom Sherwood Medical) was used to transfer about 0.1 mL or 0.2 mL ofcoating to the rheometer test area, which is a shallow circular troughhaving a depth of 0.2 mm. Afterwards, the edge of a glass slide was usedto smooth the liquid surface. A T-bar having a width of 0.28 mm and alength of 15 mm was then immersed into the liquid. The gap between thebottom of the trough and the lower part of the T-bar was 0.05 mm. Adynamic sweep of the coating was conducted at 25 rad/sec. frequency and100% strain. The rheology profiles were generated at 76° C.±1° C. and46%±2% relative humidity. The viscosity data collected for each clearcoat is shown in Table 5. The dry time (in minutes) is defined as thepoint where the clear coat viscosity reaches 4 and are shown in Table 6.Dry times also can be translated into sag resistance of the clear coat.A faster dry time indicates better sag resistance.

Samples for measuring the hardness development of the clearcoats wereprepared using the formulations as listed in Table 4. Part A componentswere added to an 8 oz. glass jar. The materials were rolled for about 24hours. The Part B crosslinker was then added to Part A and thoroughlymixed on a roller for about 30 minutes before application. A drawdowncup was used to apply a 10 mil wet film onto glass. The clearcoats werethen force-dried at 60° C.±2° C. for 20 minutes followed by ambienttemperature cure over four weeks. The hardness of the clearcoats wasdetermined after 1, 2, 7, 14, 21 and 28 days at ambient temperature andis shown in Table 6. Hardness was measured with a Tukon microhardnesstester at 20× magnification in accordance with ASTM Method D 3363.

The compatibility of the polyesters with the acrylic resin andisocyanate crosslinker in the clear coat formulation is shown in Table 6and was determined by evaluating the dry films after 60 days by percenthaze as measured with a BYK-Gardner haze-gard plus instrument inaccordance with ASTM Method D 1003, Method A.

It is desirable that the polyester, when used to replace a portion ofthe acrylic, have little or no impact on the dry time, sag resistance,hardness development or clarity of the coating. The dry times in Table 6show that example clear coat E27, containing a TMCD polyester,accelerated the dry time over comparative example clearcoats CE22, CE23and CE24. Example clearcoats E25 and E26, which contain TMCD polyesterresins, improved the dry time relative to comparative example CE23,which contains the commercial Setal polyester. The faster the coatingdries also improves the sag resistance property as well.

The Tukon hardness results in Table 6 show that clear coat examples E26and E27, which contain TMCD polyesters, exhibit early hardnessdevelopment (over the first 7 days) that is similar to comparativeexample CE22 and improved over CE23 and CE24. Over a longer term (14 to28 days), the example clearcoats containing TMCD resins develop hardnesssimilar to comparative example CE22. Comparative example clearcoats CE23(containing SETAL™ polyester) and CE24 (containing NPG polyester) werethe softest clearcoats. All of the clearcoats exhibited good clarity asmeasured by percent haze (see Table 6).

TABLE 4 Clear coat Formulations (Grams) Clear coat Example CE22 MacrynalCE23 SM 515 Setal CE24 E25 E26 E27 Example Resin Only 1603 CE4 E8 E9 E10Part A MACRYNAL SM 515/70BAC (70 wt. % in n- 64.3 57.9 57.9 57.9 57.957.9 BuOAc) (a) SETAL 1603 BA-78 (78 wt. % in n-BuOAc) (b) — 5.8 — — — —Example polyester resin (70 wt. % in n- — — 6.4 6.4 6.4 6.4 BuOAc) DABCOT-12 catalyst (10 wt. % in solvent 1.0 1.0 1.0 1.0 1.0 1.0 blend) (c)BYK 331additive (d) 1.0 1.0 1.0 1.0 1.0 1.0 IRGANOX 1010antioxidant (10wt. % in 1.0 1.0 1.0 1.0 1.0 1.0 solvent blend) (e) Solvent Blend(n-BuOAc/MAK/MEK/EB 8.3 8.6 9.0 9.0 9.0 10.1 Acetate 45:35:15:5) TotalPart A 75.6 75.6 76.3 76.3 76.3 77.4 Part B TOLONATE HDT LV (100%) (f)24.4 24.7 23.7 23.7 23.7 22.6 Total Parts A + B 100.0 100.0 100.0 100.0100.0 100.0 (a) Cytec Surface Specialties. (b) Nuplex Resins. (c) AirProducts (dibutyltindilaurate). (d) BYK-Chemie. (e) Ciba. (f) Rhodia(aliphatic polyisocyanate HDI trimer).

TABLE 5 Clear coat Viscosity Data Time Clear coat Example (mm.) CE22CE23 CE24 E25 E26 E27 0.1 0.01 0.02 0.01 0.07 0.06 0.11 1.1 0.01 0.020.01 0.07 0.06 0.16 2.1 0.02 0.02 0.02 0.07 0.07 0.22 3.1 0.04 0.02 0.030.07 0.07 0.32 4.1 0.06 0.03 0.05 0.07 0.07 0.41 5.1 0.10 0.04 0.06 0.070.07 0.42 6.1 0.17 0.05 0.10 0.08 0.07 0.61 7.1 0.23 0.07 0.15 0.08 0.081.02 8.1 0.30 0.09 0.27 0.08 0.09 1.14 9.1 0.40 0.12 0.36 0.09 0.11 1.4910.1 0.66 0.16 0.48 0.10 0.13 1.75 11.1 0.84 0.22 0.51 0.12 0.17 1.9412.1 1.08 0.25 0.74 0.14 0.20 2.10 13.1 1.20 0.26 0.94 0.17 0.24 2.3414.1 1.40 0.32 1.21 0.20 0.30 2.65 15.1 1.65 0.33 1.31 0.25 0.38 3.0716.1 1.85 0.51 1.64 0.30 0.43 3.41 17.1 2.14 0.58 1.90 0.37 0.58 3.6618.1 2.39 0.66 2.13 0.43 0.70 4.04 19.1 2.70 0.85 2.40 0.54 0.86 4.4620.1 2.96 1.07 2.68 0.61 1.01 4.91 21.1 3.33 1.22 3.06 0.79 1.21 5.4322.1 3.79 1.29 3.49 0.95 1.53 6.09 22.6 4.05 1.44 3.74 1.00 1.64 6.4123.1 4.33 1.53 4.00 1.16 1.85 6.80 24.1 5.03 1.70 4.69 1.39 2.10 7.6925.1 5.90 1.86 5.49 1.65 2.59 8.69 26.1 6.81 2.07 6.42 1.94 3.11 9.6827.1 8.03 2.22 7.54 2.32 3.53 10.84 27.6 8.71 2.32 8.18 2.50 3.97 11.4928.1 9.37 2.43 8.90 2.76 4.35 12.16 29.1 10.83 2.63 10.30 3.24 5.1313.41 30.1 12.47 2.82 11.99 3.90 6.06 14.82 30.2 12.69 2.86 12.31 3.986.24 15.09 31.1 14.28 3.04 13.77 4.47 7.09 16.30 32.1 16.08 3.29 15.585.40 8.20 17.74 33.1 18.09 3.55 17.61 6.36 9.35 19.31 34.1 20.16 3.8619.73 7.39 10.75 20.88 34.8 21.46 4.04 21.07 8.20 11.76 21.87 35.1 22.124.19 21.74 8.61 12.10 22.37 36.1 24.21 4.55 23.89 9.91 13.72 23.94 37.126.30 4.94 26.00 11.33 15.34 25.54 38.1 28.18 5.39 28.07 12.83 17.0827.07 39.1 30.17 5.89 29.94 14.40 18.84 28.50 40.1 32.05 6.46 31.8416.20 20.44 29.98 41.1 33.84 7.11 33.66 17.80 22.20 31.40 42.1 35.457.76 35.43 19.55 23.92 32.71 43.1 37.09 8.53 36.97 21.41 25.70 34.0444.1 38.63 9.40 38.51 23.19 27.30 35.33

TABLE 6 Clear coat Dry Time, Hardness Development and Clarity Clear coatExample CE22 CE23 CE24 E25 E26 E27 Example Resin Macrynal SM 515 SetalOnly 1603 CE4 E8 E9 E10 Dry Time (min.) 22.6 34.6 23.1 30.2 27.6 18.1Tukon Hardness (Knoops) After  1 Day 7.3 4.9 5.9 6.0 7.1 7.5  2 Days 8.96.0 7.1 7.4 8.0 8.2  7 Days 10.1 6.4 8.4 8.6 9.1 9.9 14 Days 11.1 6.58.6 10.0 10.0 10.4 21 Days 11.2 6.5 8.6 10.2 10.2 10.2 28 Days 11.3 6.58.4 10.2 10.2 10.2 Clear coat 0.24 0.27 0.24 0.20 0.21 0.84 ClarityAfter 60 Days (% haze)

We claim:
 1. A thermosetting coating composition, comprising: (A). about 2 to about 50 weight percent, based on the total weight of (A), (B), and (C) of a curable polyester, comprising i. diacid residues, comprising about 20 to 100 mole percent, based on the total moles of diacid residues, of the residues of isophthalic acid; ii. diol residues, comprising about 10 to 100 mole percent, based on the total moles of diol residues, of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol; and iii. about 2 to about 40 mole percent of the residues of at least one polyol, based on the total moles of diol and polyol residues; wherein said curable polyester has a number average molecular weight of about 500 to about 10,000 daltons, a glass transition temperature of about −35° C. to about 100° C., a hydroxyl number of about 20 to about 300 mg KOH/g of polyester, and an acid number of 0 to about 80 mg KOH/g of polyester; (B). about 25 to about 88 weight percent, based on the total weight of (A), (B), and (C) of at least one acrylic copolymer of ethylenically unsaturated monomers comprising at least one hydroxyl, epoxy, carboxyl, blocked phenol, or acetoacetoxy functional group; and (C). about 10 to about 50 weight percent, based on the total weight of (A), (B), and (C), of at least one crosslinker comprising at least one compound reactive with a carboxylic acid or a hydroxyl group; (D). about 10 to about 60 weight percent, based on the total weight of (A), (B), (C), and (D) of at least one non-aqueous solvent.
 2. The coating composition according to claim 1 wherein said diacid residues (i) comprise about 30 to about 70 mole percent of the residues of isophthalic acid, and further comprise about 70 to about 30 mole percent of the residues of adipic acid; and said diol residues (ii) comprise about 20 to 100 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol.
 3. The coating composition according to claim 2 wherein said diacid residues (i) comprise about 40 to about 60 mole percent of the residues of isophthalic acid and about 60 to about 40 mole percent of the residues of adipic acid.
 4. The coating composition according to claim 1 wherein said diacid residues (i) further comprise up to 30 mole percent of the residues of at least one dicarboxylic acid chosen from phthalic acid, terephthalic acid, tetrachlorophthalic acid, dodecanedioic acid, sebacic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, maleic acid, fumaric acid, succinic acid, 2,6-naphthalenedicarboxylic acid, and glutaric acid.
 5. The coating composition according to claim 1 wherein said diol residues (ii) further comprise up to 90 mole percent of the residues of at least one diol chosen from neopentyl glycol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethyl-hexane-1,3-diol, 2,2-dimethyl-1,2-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2,4-tetramethyl-1,6-hexanediol, thiodiethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4-trimethyl 1,3-pentanediol, p-xylenediol, hydroxypivalyl hydroxypivalate, 1,10-decanediol, and hydrogenated bisphenol A.
 6. The coating composition according to claim 1 wherein said polyol residues (iii) comprise about 3 to about 30 mole percent of the residues of at least one polyol chosen from trimethylolpropane, pentaerythritol, trimethylolethane, erythritol, threitol, dipentaerythritol, sorbitol, and glycerine.
 7. The coating composition according to claim 1 wherein said curable polyester comprises about 50 to about 100 mole percent of the residues of isophthalic acid, 0 to about 50 mole percent of the residues of adipic acid, about 100 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 10 mole percent of the residues of trimethylolpropane, wherein said curable polyester has a hydroxyl number of about 30 to about 250 mg potassium hydroxide per gram of polyester, an acid number of about 2 to about 15 mg potassium hydroxide per gram of polyester, a Tg of about −20 to about 50° C., and a number average molecular weight of about 700 to about 7000 daltons.
 8. The composition of claim 1, wherein said ethylenically unsaturated monomers of the acrylic copolymer (B) are chosen from at least one of acrylate, methacrylate, styrene, (meth)acrylic acid, and vinyl esters.
 9. The coating composition according to claim 1 wherein said crosslinker (C) comprises at least one compound chosen from epoxides, melamines, isocyanates, and isocyanurates.
 10. The coating composition according to claim 9 wherein said crosslinker (C) comprises at least one epoxide compound chosen from epoxy resins containing bisphenol A, epoxy novalac resins, epoxy resins containing bisphenol F, and triglycidylisocyanurate.
 11. The coating composition according to claim 9 wherein said crosslinker (C) comprises at least one melamine compound chosen from hexamethoxy-methylmelamine, tetramethoxymethylbenzoguanamine, tetramethoxymethylurea, and mixed butoxy/methoxy substituted melamines.
 12. The coating composition according to claim 9 wherein said crosslinker (C) comprises at least one compound chosen from toluene diisocyanate, isocyanurates of toluene diisocyanate, diphenylmethane 4,4′-diisocyanate, isocyanurates of 4,4′-diisocyanate, methylenebis-4,4′-isocyanatocyclohexane, isophorone diisocyanate, isocyanurates of isophorone diisocyanate, the biuret of 1,6-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, isocyanurates of 1,6-hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, p-phenylene diisocyanate, and triphenylmethane 4,4′,4″-triisocyanate, tetramethyl xylene diisocyanate, metaxylene diisocyanate, polyisocyanates, 1,4-butylene diisocyanate, methylene bis(4-cyclohexyl isocyanate), isophorone diisocyanate and isocyanate-terminated adducts of ethylene glycol, 1,4-butylene glycol, and trimethylol propane.
 13. The coating composition according to claim 1 wherein said solvent (D) comprises benzene, xylene, mineral spirits, naphtha, toluene, acetone, methyl ethyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, n-butyl acetate, isobutyl acetate, t-butyl acetate, n-propyl acetate, isopropyl acetate, ethyl acetate, methyl acetate, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, ethylene glycol monobutyl ether, propylene glycol n-butyl ether, propylene glycol methyl ether, propylene glycol monopropyl ether, dipropylene glycol methyl ether, diethylene glycol monobutyl ether, trimethylpentanediol mono-isobutyrate, ethylene glycol mono-octyl ether, diacetone alcohol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, or combinations thereof.
 14. The coating composition according to claim 1 which comprises about 25 to about 35 weight percent of said solvent (D) and about 20 to about 35 weight percent of said crosslinker (C), wherein said crosslinker (C) comprises hexamethoxymethylmelamine.
 15. The coating composition according to claim 1 further comprising at least one coating additive chosen from leveling agents, rheology agents, flow control agents, plasticizers, flatting agents, pigment wetting and dispersing agents, crosslinking catalysts, pigments, dyes, ultraviolet light absorbers, ultraviolet light stabilizers; defoaming agents, antifoaming agents, anti-settling agents, anti-sag agents, bodying agents, anti-skinning agents; anti-flooding agents, anti-floating agents, and corrosion inhibitors.
 16. A shaped object coated with the coating composition of claim
 1. 